1. ## Ciclre/Trig Help please ????

Please help, I have my exam on Friday and really need to know how to solve the 2003 Standard Grade Paper, Question 10.

question: A sheep shelter is part of a cylinder thats is 6 meters
wide and 2 meters high. The cross section of the shelter is a segment
of a circle with centre, O. Calculate the radius of the circle?

2. ## Circle Attachment

Maybe this pic will help?

3. ## And the next step (I Think!)

I think this is the right direction ?

4. Originally Posted by kenj
Maybe this pic will help?
Hello,

You see a right triangle with the hypotenuse of 2r. Then the half chord is the height in the right triangle.

In a right triangle the product of the two parts of the hypotenuse equals the square of the height:
$2\cdot (2r-2)=3^2 \Longleftrightarrow 4r-4=9 \Longleftrightarrow r = \frac{13}{4}$

Greetings

EB

5. Many thanks.

6. Originally Posted by kenj
Please help, I have my exam on Friday and really need to know how to solve the 2003 Standard Grade Paper, Question 10.

question: A sheep shelter is part of a cylinder thats is 6 meters
wide and 2 meters high. The cross section of the shelter is a segment
of a circle with centre, O. Calculate the radius of the circle?
Use the intersecting chord theorem.

In this case it tell us that:

$
3\times 3=2\times(2r-2)
$

where $r$ is the radius of the circle.

RonL

7. Many thanks for your help. Thanks to your posts I also completed it just by using Pythagoros. Such that:

3sq + (r-2)sq = rsq

So 9 + rsq -2r – 2r + 4 = rsq

13 = 4r

r = 13 / 4 = 3.25